A Simple Synthesis of 1,3-Diphenylpropene
R. N. Shakhmaev*, A. Sh. Sunagatullina, A. N. Vasilyeva, and V. V. Zorin
Ufa State Petroleum Technological University, ul. Kosmonavtov 1, Ufa, 450062 Russia
Received October 26, 2017
Abstract—A simple approach to the synthesis of 1,3-diphenylpropene isomers was developed based on
-catalyzed cross-coupling of (E)- and (Z)-1,3-dichloropropenes with phenylmagnesium bromide.
Keywords: 1,3-diphenylpropene, cross-coupling, Fe-catalyzed cross-coupling, Fe(acac)
TO THE EDITOR
ISSN 1070-3632, Russian Journal of General Chemistry, 2018, Vol. 88, No. 2, pp. 342–344. © Pleiades Publishing, Ltd., 2018.
Original Russian Text © R.N. Shakhmaev, A.Sh. Sunagatullina, A.N. Vasilyeva, V.V. Zorin, 2018, published in Zhurnal Obshchei Khimii, 2018, Vol. 88,
No. 2, pp. 346–348.
1,3-Diphenylpropene isomers are used in organic
synthesis as the starting substrates and model
compounds [1–4]. The specific reactivity of 1,3-di-
phenylpropene is due to the presence of methylene
group, being simultaneously in the allyl and benzyl
positions. (E)-1,3-Diphenylpropene is usually obtained
by treating a not easily accessible phenylacetaldehyde
with a KOH alcohol solution [5, 6], while the synthesis
of less thermodynamically stable (Z)-isomer with an
acceptable stereochemical purity is very problematic
We investigated the possibility of obtaining 1,3-
diphenylpropene 2 by Fe(acac)
coupling of 1,3-dichloropropene 1 with phenylmag-
nesium bromide. It is known that available iron(III)
salts are effective catalysts in cross-coupling reactions
of Grignard reagents with vinyl [9-–12] and allyl
halides [13, 14]. Fe(acac)
the most commonly used in
the synthesis of natural compounds [15, 16] and drugs
[17–20] is advantageously characterized by low hygro-
scopicity, good solubility, and ease of handling .
The reaction of (E)-1,3-dichloropropene la with
3 equiv of PhMgBr in tetrahydrofuran in the presence
of 3 mol % of Fe(acac)
afforded a mixture of (E)- and
(Z)-isomers of 1,3-diphenylpropene 2a and 2b (E : Z =
92 : 8) in a 52% yield. The introduction of the most
frequently used ligands like N,N,N,N-tetramethylethyl-
enediamine (TMEDA)  or N-methylpyrrolidone
(NMP) , the replacement of THF by diethyl ether
and the use of FeCl
as the catalyst did not sub-
stantially increase the yield of the reaction product.
However, a decrease in the reaction temperature to
–35°C results in an increase in the yield of 1,3-diphenyl-
propene to 80% with the same isomeric composition.
The cross-coupling with (Z)-1,3-dichloropropene
under similar conditions resulted in an isomeric mixture
of 1,3-diphenylpropene (E : Z = 55 : 45) with 72%
yield, while at room temperature the reaction direction
shifted toward the formation of (E)-isomer (E : Z =
76 : 24). (E)- and (Z)-isomers of 1,3-diphenylpropene
and diphenyl formed by homocoupling reaction were
separated by column chromatography (Scheme 1).
Structure and purity of the obtained compounds
was confirmed by high-performance GLC analysis,
NMR spectroscopy and chromato-mass spectrometry.
A reliable evidence of the stereochemical configura-
tion of isomers 2a and 2b was the values of spin-spin
coupling constant of vinyl hydrogen atoms (J = 15.6
and 11.3 Hz), characteristic of the E- and Z-con-
figurations, respectively. In addition, the signal of the